WPR10CA398

NTSB accident investigation · Kirkpatrick Buzzard · Lincoln, CA · August 4, 2010

Accident · Serious injuriesData collectionFinal report
Date
August 4, 2010, 12:30 local (19:30 UTC)
Place
Lincoln, CA
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N84BSKirkpatrick Buzzard
Defining event
Initial climb: Flight control sys malf/fail
Weather
Visual (VMC) · Day
Status
Completed · report January 7, 2011
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
Federal Aviation Administration FSDO
FAA report
20100804042359A
Case key
76944

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

A loss of control due to the mechanical disconnection of an aileron pushrod from its bellcrank as a result of the mechanic's failure to properly secure the pushrod attach hardware. Also causal was the pilot's inadequate preflight inspection.

Findings · 4

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Flight control system: aileron control systemAircraft › Aircraft systems · Incorrect service/maintenanceKirkpatrick Mark S BUZZARD 1 MOTORGLIDE: 1 caseAll aircraft: 45 casesProbable cause
Maintenance: fabricationPersonnel issues › Task performance · Maintenance personnelKirkpatrick Mark S BUZZARD 1 MOTORGLIDE: 1 caseAll aircraft: 30 casesProbable cause
Performance/control parametersAircraft › Aircraft oper/perf/capability · Attain/maintain not possibleKirkpatrick Mark S BUZZARD 1 MOTORGLIDE: 1 caseAll aircraft: 1,269 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The single-seat aircraft was registered with the Federal Aviation Administration (FAA) as an experimental, amateur-built aircraft. A week before the accident, the aircraft was assembled by a certificated aircraft mechanic. The pilot reported that he had previously flown the aircraft one time, for about 30 minutes. During the accident flight's takeoff roll, the pilot noticed that the aircraft did not "feel right," but he opted to continue. About 250 feet above the ground the outboard right wing "started to flutter in a violent way" and in response the pilot reduced engine power and aircraft speed. He then "lost all control." The aircraft impacted the ground in a field and seriously injured the pilot. About an hour after the accident skydivers noticed the wreckage and summoned emergency services to rescue the pilot. Examination of the wreckage by an FAA inspector revealed that the bolt that was supposed to attach an aileron pushrod to the outboard aileron bellcrank was lying loose in the bottom of the wing bay; neither the nut nor the cotter pin was recovered. Examination of the opposite aileron bellcrank revealed that the corresponding bolt and nut were not secured by a cotter pin, despite provisions for one. The mechanic who assembled the aircraft stated that he did not install cotter pins in either of the two noted bolts. The pilot stated that he did not inspect the aircraft after assembly or before the flight.

Factual narrative

The student pilot/owner reported that he had about 329 total hours of flight experience, including 250 hours in single-engine airplanes, 58 hours in ultralight aircraft, and 21 hours in gliders. He stated that the accident aircraft was a modified version of the Kolb Firefly ultralight. The single-seat aircraft was registered with the Federal Aviation Administration (FAA) as an experimental amateur-built "Buzzard 1 Motorglider." A week before the accident, the aircraft was assembled by a certificated aircraft mechanic. The pilot reported that he had previously flown the aircraft one time, for about 30 minutes. During the accident flight takeoff roll, the pilot noticed that the aircraft did not "feel right," but he opted to continue. About 250 feet above the ground, the outboard right wing "started to flutter in a violent way," and in response, the pilot reduced engine power and aircraft speed. He then "lost all control." The aircraft impacted the ground in a field, and seriously injured the pilot. About 1 hour after the accident, skydivers noticed the wreckage, and summoned emergency services to rescue the pilot. Examination of the wreckage by an FAA inspector revealed that the bolt that was supposed to attach an aileron pushrod to the outboard aileron bellcrank was lying loose in the bottom of the wing bay; neither the nut nor the cotter pin was recovered. Examination of the opposite aileron bellcrank revealed that the corresponding bolt and nut were not secured by a cotter pin, despite provisions for one. The mechanic who assembled the aircraft stated that he did not install cotter pins in either of the two noted bolts. The pilot stated that he did not inspect the aircraft after assembly, or before the flight.

Aircraft

Registration
N84BS
Reported as
Kirkpatrick Buzzard (1)
Category
Airplane, amateur-built
Serial number
001
Airframe hours
0
Engine
Rotax 442, 40 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Condition · July 15, 2010 · 0 hours before
Departed
LHM · Lincoln, CA
Destination
LHM · Lincoln, CA
Flight plan
Unknown
Airport
LHM · Lincoln Regional, runway 15, 6,001 × 100 ft, asphalt

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
82
Injuries
Serious
Certificate
Student
Seat
Single
Flight hours
329 total · 0 in this make and model

Weather

Conditions
Visual (VMC) · Day
Visibility
10 statute miles
Lowest ceiling
None

Docket · 5

The files NTSB released with the investigation on September 27, 2010, on NTSB’s docket system: statements, records, photos and specialists’ reports. 3.8 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.